CMake/Source/cmUVSignalHackRAII.h
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2018-06-01 09:53:42 -04:00

46 lines
1.4 KiB
C++

/* Distributed under the OSI-approved BSD 3-Clause License. See accompanying
file Copyright.txt or https://cmake.org/licensing for details. */
#pragma once
#include "cmConfigure.h" // IWYU pragma: keep
#include "cm_uv.h"
#if defined(CMAKE_USE_SYSTEM_LIBUV) && !defined(_WIN32) && \
UV_VERSION_MAJOR == 1 && UV_VERSION_MINOR < 19
# define CMAKE_UV_SIGNAL_HACK
# include "cmUVHandlePtr.h"
/*
libuv does not use SA_RESTART on its signal handler, but C++ streams
depend on it for reliable i/o operations. This RAII helper convinces
libuv to install its handler, and then revises the handler to add the
SA_RESTART flag. We use a distinct uv loop that never runs to avoid
ever really getting a callback. libuv may fill the hack loop's signal
pipe and then stop writing, but that won't break any real loops.
*/
class cmUVSignalHackRAII
{
uv_loop_t HackLoop;
cm::uv_signal_ptr HackSignal;
static void HackCB(uv_signal_t*, int) {}
public:
cmUVSignalHackRAII()
{
uv_loop_init(&this->HackLoop);
this->HackSignal.init(this->HackLoop);
this->HackSignal.start(HackCB, SIGCHLD);
struct sigaction hack_sa;
sigaction(SIGCHLD, nullptr, &hack_sa);
if (!(hack_sa.sa_flags & SA_RESTART)) {
hack_sa.sa_flags |= SA_RESTART;
sigaction(SIGCHLD, &hack_sa, nullptr);
}
}
~cmUVSignalHackRAII()
{
this->HackSignal.stop();
uv_loop_close(&this->HackLoop);
}
};
#endif